Novel dehydrofluorination reactions accidentally found were used to synthesize terminal monofluoro olefin lactam analogues in good yield. The following hydrogenation of the resulting defluorinated product was systematically investigated. Two important fluorinated amino acids: 4-monofluoromethylenyl-L-pyroglutamic acid 16 and cis-4-monofluoromethyl-L-pyroglutamic acid 17 were synthesized using the methodology. (C) 2004 Elsevier Ltd. All rights reserved.